Mopar Push Button Reverse Switch

When you press the R button on the dash gear selector the movement
throws a small switch mounted on the push button assembly, lighting the
backup lights. Pushing any forward button moves the switch to the OFF
position.

Left: Switch at 3-4 oclock position; Right, at 1-2 oclock position

Kevin M. adds: The description is fine for 1962 to 1964 Mopars. There were no push buttons in 1965 and the switch for
the console cars in 1964 and 1965 is different.

The back up light switch will activate the back up lights before the reverse button is depressed enough to actually shift the tranny.